I have a 2007 V-8 Quad-cab Dakota that I bought about 3 years ago. I live in the Great White North and my truck has a quirk where it won't start after sitting outside overnight in approximately -20C/-4F temperatures or colder. It cranks over just fine but WILL NOT FIRE. If I plug in the block heater for about 30 minutes, it starts just fine.

I took it to a shop and they hooked it up to their wizard box, but of course it didn't fail while it was there so they found nothing. But they did mention something about a sensor that is located deep down on the engine block that, under certain conditions, will intentionally prevent the engine from starting.

I am wondering if this sensor is a bit dodgy and erroneously sends a "no start" signal in very cold temperatures, but a bit of warmth from the block heater is enough to restore normal operation.

Does anybody know anything about this sensor, or have any other ideas about this problem?

 

Never heard of it.

 

I would call them back and ask what sensor they are referring to.